Life of Cyanotype Chemistry?

Discussion in 'Alternative Processes' started by bjorke, Jan 2, 2005.

  1. bjorke

    bjorke Member

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    We have a batch of chemicals that have been shelved for about a year. Are they worth keeping at this point?

    T.I.A.,
     
  2. donbga

    donbga Member

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    Most likely they will be fine. Mix 'em up and give it a whirl.

    Don Bryant
     
  3. 127

    127 Member

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    Dry they should be fine. Once you've made the solutions one part keeps for a year or so, while the other goes funny after about a month (I forget which is which, but it's VERY obvious - looks like stuff growing in it).

    Once you've mixed the two parts they keep a day or two.

    Ian
     
  4. Ole

    Ole Moderator Staff Member Moderator

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    My solutions are both fine after 8 months - nothing "gone funny" at all. Maybe the smidgeon of oxalic acid I added to each works as a preserving agent?
     
  5. Joe Lipka

    Joe Lipka Member

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    Luddite, Ha! You are much more technically adanced than that! Oxalic Acid works just fine to kill that funky stuff that grows in one of the solutions.

    I ran into the same problem, but the stuff that was growing inside the bottle was able to keep me from opening the bottle and disposing of the stuff.

    We are now in our second year of a truce.
     
  6. Aggie

    Aggie Member

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    Similar question about Van Dyke solution once mixed. Will it keep for very long? (Don't laugh) mine is just over 3 years old. It's well aged
     
  7. hermit

    hermit Member

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    I am using cyanotype solutions now 13 months old with no problems what so ever.
     
  8. donbga

    donbga Member

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    I've never found this to be true. Mixed and stored properly they will last a long time. Store in dark glass jugs. Usually the biggest problem will be mold growth in Part A which can be eliminated with the addition of a few drops of a 100% solution of thymol.

    Lately I've been using a 1/2 liter mix made over a year ago for the cyan layer of tri-colored gums.

    Don Bryant
     
  9. donbga

    donbga Member

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    Aggie,

    I usually use my solutions of VDB quicker than that but I've found that sometimes an older VDB mix just seems to peter out. The best test is to try it and see. Bad VDB solutions print gray and flat, if it comes out red-brown you are okay. VDB is so inexpensive though that losing a small mix to age doesn't hurt the pocket book too much.

    Don Bryant